Several medical procedures involve positioning a catheter, such as a feeding tube or endoscope, within a patient through the patient's nose, mouth, or other opening. In many procedures, accurately positioning the catheter is crucial to the success of the procedure and/or to the safety of the patient. For example, a nasogastric (NG) feeding tube may be inserted through the nose, past the throat, and down into the stomach, or past the stomach into the small bowels of the patient to deliver food to the patient via the tube. If the feeding tube is mistakenly positioned in the patient's lung, the feeding solution would be delivered to the patient's lung causing critical and possibly fatal results.